The present invention relates to a support assembly and more particularly to a unique and useful construction for a collapsible-expansible rolling scaffold assembly.
Support structures which include two or more pivotally connected structural parts have been long known in the support and scaffolding arts, attention being directed to the pivotal fold-up tower assembly of long since expired U.S. Pat. No. 3,011,586, issued to J. E. Harvey, Jr. on Dec. 5, 1961; to the pivotal support bracket of U.S. Pat. No. 3,493,208, issued to M. Sato on Feb. 3, 1970; to the pivotally collapsible walker assembly of U.S. Pat. No. 3,516,425, issued to W. A. Rigal on Jun. 23, 1970; to the collapsible bed rail structure of U.S. Pat. No. 3,616,469, issued to S. G. Injeski on Nov. 2, 1971; to the boat boarding ladder structure of U.S. Pat. No. 3,858,683, issued to E. Rachocki on Jan. 7, 1975; to the scaffold coupling structure of U.S. Pat. No. 4,439,052, issued to H. Wallther on Mar. 27, 1984; and finally to the collapsible scaffold structure which includes a window and projection structure extending through the window, the window sides limiting relative movement of pivotally connected distal ends of a truss assembly for the scaffold, as shown in U.S. Pat. No. 4,609,071, issued to P. M. Edwards on Sep. 2, 1986.
The present invention provides an improved collapsible-expansible support assembly structure over the prior art structures which inventive structure includes a unique structural support arrangement that is straightforward, efficient and economical to manufacture, assemble and maintain, requiring a minimum of comparatively inexpensive and efficiently operable parts. In addition the support structure of the present invention is comparatively light in weight, readily portable and easily storable, requiring a minimum of space. Further, the support structure of the present invention can be easily and readily erected from a collapsible to an expansible mode and vice versa, at the same time automatically restricting and locking the structure in a preselected, stable position when the mode has been selectively changed. Moreover, the present invention provides a unique, protective shield structure over certain otherwise undesirably exposed areas during mode change and also provides a novel caster assembly and support plank arrangement to further insure support stability. Although the structural features of the present invention, including the facility of assembly to each other of vertical and horizontal structural members have particular uniqueness in the scaffolding arts, it is to be understood that many of the novel structural features disclosed herein can be of significant use in other structural support arrangements.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.